Lateral root

Lateral Root emerging from the pericycle (blue) in a cross-section of Iris germanico root

Lateral roots, emerging from the pericycle (meristematic tissue), extend horizontally from the primary root (radicle) and over time makeup the iconic branching pattern of root systems.[1] They contribute to anchoring the plant securely into the soil, increasing water uptake, and facilitate the extraction of nutrients required for the growth and development of the plant.[2] Lateral roots increase the surface area of a plant's root system and can be found in great abundance in several plant species.[1] In some cases, lateral roots have been found to form symbiotic relationships with rhizobia (bacteria) and mycorrhizae (fungi) found in the soil, to further increase surface area and increase nutrient uptake.[1]

Several factors are involved in the formation and development of lateral roots. Regulation of root formation is tightly controlled by plant hormones such as auxin, and by the precise control of aspects of the cell cycle.[3] Such control can be particularly useful, as increased auxin levels help to promote lateral root development, in young leaf primordia. This allows coordination of root development with leaf development, enabling a balance between carbon and nitrogen metabolism to be established.

  1. ^ a b c Taiz, Lincoln (2018). Fundamentals of Plant Physiology. Cary, NC, USA: Oxford University Press. ISBN 9781605357904.
  2. ^ Santos Teixeira, J.A.; ten Tusscher, K.H. (February 2019). "The Systems Biology of Lateral Root Formation: Connecting the Dots". Molecular Plant. 12 (6): 784–803. doi:10.1016/j.molp.2019.03.015. ISSN 1674-2052. PMID 30953788.
  3. ^ Malamy, Jocelyn E.; Benfey, Philip N. (October 1997). "Down and out in Arabidopsis: the formation of lateral roots". Trends in Plant Science. 2 (10): 390–396. doi:10.1016/s1360-1385(97)90054-6. ISSN 1360-1385.